3.3 Projectile Motion

1. 3.3 Projectile Motion

2. Projectile Motion • The path of a thrown baseball, shot basketball, or hit volleyball is a parabola. • Projectiles • Object in flight only under influence of gravity • Follows parabolic path

3. vx vy Projectile Motion • Consider x and y separately • x • No acceleration ax = 0 • vx remains constant • y • a = -9.80 m/s2 • vy changes

4. On Top of Spaghetti… • A meatball with v = 5.0 m/s rolls off a 1.0 m high table. How long does it take to hit the floor? • t = 0.45 s • What was the velocity when it hit? • v = 6.7 m/s @ 42°

5. The Falling Box • A truck (v = 11.2 m/s) turned a corner too sharp and lost part of the load. A falling box will break if it hits the ground with a velocity greater than 15 m/s. The height of the truck bed is 1.5 m. Will the box break? • v = 12 m/s, No it doesn’t break.

6. Reasoning Strategy • For Projectile Motion • Deal with y before x • Find time of flight 1st

7. I Shot a Bullet into the Air… • While driving down a road a bad guy shoots a bullet straight up into the air. If there was no air resistance where would the bullet land – in front, behind, or on him? • If air resistance present, bullet slows and lands behind. • No air resistance the vx doesn’t change and bullet lands on him.

8. Height of a Fly Ball • A batter hits a ball at 35° with a velocity of 32 m/s. How high did the ball go? • H = 17 m • How long was the ball in the air? • t = 3.8 s • How far did the ball go? • x = 98 m

9. Practice Work • You should be able to attempt • 74 #CQ2 – 8, 10, P13, 15 – 20, 22, 24, 27, 29, 31, 33 • Total of 21 problems (come to class to work on problems tomorrow) • This assignment worth double points!